1. by what factor will the electrostatic force between two charged objects change when the amount of charge on one object doubles?
a. 2
b. 4
c. 1/2
d. 1/4
2. by what factor will the electrostatic force between two charged objects change when the distance between the two charged objects doubles?
a. 2
b. 4
c. 1/2
d. 1/4
3. by what factor will the electrostatic force between two charged objects change when the amount of charge on both objects doubles and the distance between the two charged objects triples?
a. 2/3
b. 3/4
c. 2/9
d. 2/9

1) A. 2

The electrostatic force between two objects is given by:

where

k is the Coulomb's constant

q1 and q2 are the charges of the two objects

r is the separation between the two objects

In this problem, the charge of one object is doubled, so

Therefore the new force is

So, the force will double.

2) D. 1/4

Using the same formula, the electrostatic force between the two objects is:

In this problem, the distance between the two objects is doubled, so

Therefore the new force is

So, the force will decrease to 1/4 of its original value.

3) 4/9

Using the same formula, the electrostatic force between the two objects is:

In this problem, the amount of charge on both objects doubles, so

Also, the distance is tripled

Therefore the new force is

So, the force will decrease to 4/9 of its original value.

answer: 2×10^-2kg

explanation: density= mass per volume

vol=mass/density

converting to s.i units we have;

3÷1000kg = 0.003

1.5÷100m = 0.15

0.003/0.15 = 0.02kg

one "light year" is the distance that light travels, through vacuum, in one julian year.   that's 365.25 days, of 24 hours each.